I will try to update what is going on @ Teramot-san's development room!
All Finemet Field coil Power Supply:
We were making small change on drivers for refinement. However revolutionary change was happened on field coil power supply.

We just delivered a custom designed unit to an customer in USA, and he was extremely happy about the result. Once I get his permission, I will post his impression on here.

The field coil power supply has zero feedback, zero electrolytic capacitor, All Finemet transformer and Chokes.

The best part of this power supply is sound stage and decay of the sound. How sound is disappearing to the space is amazing! I tried constant current, constant voltage... etc but never had success of this level.

We are using similar power supply for our DAC and the result is one big smile!

Now his CD player is taking vacation. Newly delivered Bumpei-san's SDTrans + Buffalo DAC is on his reference digital system now. It uses Finemet DAC output transformers for I/V low pass stage on ES9018, and power supply uses two custom Finemet power transformers and chokes.

While we were developing DAC output transformer for ES9018. Many people were requesting development for AK4399 (4396) and PCM1795 (1794).

Now transformers for ES9018 and AK4399 are available, and PCM1795 are in beta testing.

We tested various digital filter setting on ES9018 while watching FFT spectrum on screen, the best result was no digital filter. We can clearly see the digital filter is doing their job on the screen, but visual result was not reflecting to positive listening result.

We also tested different power supplies. What we learned is that quality of the power supply and output (I/V low pass) stage make bigger difference than type of DAC chips.

Urushi Capacitor:
Last year we evaluated many different capacitors on the market. I mean we spent some hard earned money just for testing, more than a pair of TA300B

Finemet transformer is very transparent, you can hear phase shift (or non stability) on coupling capacitor and power supply capacitors, and chokes... Replacing only output transformers to Finemet and keeping electrolytic capacitors, PIO capacitors, orient core chokes etc..., usually does not work well, we can hear too much of the negative characteristics of the rest of the amplifier.

For the best result, we need to evaluate all the component in the amplifier. We measured static and dynamic phase response of the capacitor. Once the capacitor pass the measurement, we put them into the circuit and performed some listening test.

After the both testing, we found some good ones, but not a perfect one, and Teramoto-san did some magic, Urushi finish capacitors. If we touch Urushi before it gets dry, it will act like a poison ivy juice. You will never forget the experience! You can try DIY, but hell! I will not try this at home!

Now all Feastrex Maekawa amplifier use Urushi capacitors.

All Finemet Amplifier:
Feastrex is using Finemet output transformer for several years now. In the beginning we used only the output transformer, then power supply choke, now also power transformer... Now we use them for everything!

Feastrex builds amplifier for Feastrex speaker owners, not for general public. They just do not have production capability at this moment.

We are working on All Finemet 300B SET with Takatsuki TA-300B made in Japan. All the custom Finemet transformers and Teramoto-san's special treatment are done. Now we are waiting for Maekawa-san, great amp builder @ Feastrex for assembling them and shipping to USA!!

I am thinking about putting transformers in shielded case for avoid shipping damage. Is this OK or do you want to receive them as naked? (using shielded case is strongly recommended by our transformer designer.)

Demo Transformer process:
1. You send me PM for demo transformer request
2. I will send you my shipping address.
3. You send me a check for $1030
4. Once I receive your check, your name will be on the waiting list.
5. You enjoy the demo unit.
6. Write your review on this thread.
7. You will ship demo unit to next DIYer.
8. Once delivery is confirmed, I will dispose your check.

If you have any comment or suggestions, please let me know!

These pictures should show how transformer looks like, and How I am testing these transformers in the case. The bottom picture shows testing beta PCM1795 DAC transformer with DAC from Raleigh Audio (K & K Audio).

The images seem to be gone as I cannot open any of them. Would you please re-post them?

/S

Quote:

Originally Posted by fulken

For sending demo unit around, I have couple of questions.

Do you think one week evaluation period is long enough, or need more?

I am thinking about putting transformers in shielded case for avoid shipping damage. Is this OK or do you want to receive them as naked? (using shielded case is strongly recommended by our transformer designer.)

Demo Transformer process:
1. You send me PM for demo transformer request
2. I will send you my shipping address.
3. You send me a check for $1030
4. Once I receive your check, your name will be on the waiting list.
5. You enjoy the demo unit.
6. Write your review on this thread.
7. You will ship demo unit to next DIYer.
8. Once delivery is confirmed, I will dispose your check.

If you have any comment or suggestions, please let me know!

These pictures should show how transformer looks like, and How I am testing these transformers in the case. The bottom picture shows testing beta PCM1795 DAC transformer with DAC from Raleigh Audio (K & K Audio).